Fastening device



' Oct. 26, 1954 L; H. FLORA FASTENING DEVICE Filed Nov. 1, 1951 I INVENTOR. Q' L ,mmwcz H F BY n C v {7,,,ZZ Jen/1e X %7flea/x- Patented Oct. 26, 1954 FASTENING DEVICE Laurence H. Flora, Cleveland, Ohio, assignor to Tinnerman Products Inc., Cleveland, Ohio, a

corporation of Ohio Application November 1, 1951, Serial No. 254,408

1 Claim.

This invention relates to a clamping device, and particularly to a harness clamp which is adapted for holding in place a bundle of insulated wires, such as are used, for example, in airplane construction.

A device suitable for accomplishing the foregoing purpose embodies a strap one end of which is aflixed to a holder and the other end, after passing around a bundle of wires, is adapted to be passed beneath a roller and squeezed against the other end of the strap upon advancement of the roller into clamping position. A strap heretofore used for such purpose has been formed with smooth surfaces, as a result of which some difficulty has been experienced in retaining the strap ends against slippage with respect to each other.

An object of the present invention is to provide the inter-engaging surfaces of the strap with interlocking shoulders, which permit the free end of the strap to be pulled as tightly as desired, but which resists movement in the opposite direction, whereby the bundle of Wires may be eifectively and easily maintained in clamped position.

Briefly, the invention is carried out by providing a saw tooth construction on the interior longitudinal surface of the strap, wherein each tooth has one face extending substantially at a right angle to the plane of the outer surface, and has the other face inclined from the point of the tooth to the base of an adjacent tooth. The inclined faces extend towards the point of anchorage, whereby the teeth on the free end of the strap will slide over those on the fixed end during the clamping operation, and will interlock therewith in such manner that the two portions in contiguous engagement are in effect one integral piece.

In the drawings, Fig. 1 is a, perspective view of a clamping device embodying the construction of the present invention; Fig. 2 is a vertical section taken longitudinally through a portion of the device of Fig. 1, and illustrating on an enlarged scale the inter-locking construction of the coacting shoulders on the strap.

My device is shown in connection with a holder which has a base ID, that is adapted to be fastened to a support H by a securing member I2. The holder has side portions l3, each of which has a slot M in which a roller I5 is journalled. The slots extend upwardly and rearwardly, whereby the roller, when moved to the upper-most portion, allows the free end 20 of a strap to be passed between it and the fixed portion 2| of the strap.

The end 2| of the strap is fixed to the holder III by the same securing member I2 which operates to attach the holder to a support, and the strap then extends longitudinally along the base of the holder, around the bundle of wires indicated at 25 and beneath a guiding lip 26 on the forward and upper end of the holder, then beneath the roller I5 after which it may be pulled as tightly as desired around the bundle.

To hold the free end of the strap in desirable locking engagement with the fixed end portion thereof, I provide inter-locking shoulders preferably in the form of saw-teeth on the inner longitudinal surface of the strap. Each tooth has one face 31 lying in a plane which extendslsubstantially normal to the plane of the outer surface, and has the other face 32 inclined from the point of the tooth to the base of an adjacent tooth. Additionally the inclined faces extend in such manner that the faces 32 slope upwardly towards the fixed end as is shown in Fig. 2. Thus, the inclined faces ride freely over each other whenever the free end of the strap is passed beneath the roller l5 and is pulled tightly around a bundle of wires. The clamping action is completed by sliding the roller downwardly in the slot I4 whereby a camming action between the roller and the upper walls of the slots operates to force the shoulders on the free end of the strap into interlocking engagement with those on the fixed end of the strap, thus, in effect, making the contiguous portions one integral strip.

The form of holder or clamp shown is merely illustrative, it being understood that the strap may be used with other forms of adjustable clamps.

An advantage of the present invention is the minimizing of the liability of loosening due to excessive vibration such as might be present in an airplane. The invention has solved a dimcult problem in maintaining a tight clamping engagement with a bundle of wires, particularly after the clamp has been in use for any extended length of time. The interlocking shoulders are capable of being readily released whenever desired, or of being quickly tightened in the event of shifting of any of the wires in the bundle after an initial clamping adjustment.

I claim:

In a clamping device, the combination of a base having raised wings on opposite sides defining an open-ended strap receiving guide therebetween and each wing having a slot inclined upwardly from one open end of the guide adjacent the base towards the other open end adjacent the top of each wing, a roller disposed transversely between the raised wings and having its ends extending 3 loosely through the adjacent wing slots respectively, whereby said roller may be freely positioned along the slot from a position against the base to a position spaced vertically therefrom, and a strap having one end fixed to the base between the raised wings and the other end adapted to be passed around an article externally positioned adjacent said one open end of the guide and looped back through the guide beneath said roller in overlapping relation to the fixed end thereof, the outer longitudinal surface of said strap being smooth for camming coaction against the overlying roller and the inner longitudinal surface of the strap having regularly spaced transverse shoulders forming a ratcheted surface thereon, each shoulder being inclined gradually towards the other open end of the guide and dropping abruptly into the next succeeding shoulder, whereby the shoulders on the overlapping end of the strap when looped about the article are disposed in inverted reversed position relative to the shoulders on the fixed portion of the strap and are adapted to engage each other in interlocking relation under the camming pressure of the roller acting against the smooth surface of the strap.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 983,093 Svenson et al. Jan. 31, 1911 1,173,998 Depew Feb. 29, 1916 1,804,725 Walker May 12, 1931 2,491,290 Tinnerman Dec. 13, 1949 FOREIGN PATENTS Number Country Date 4,259 Great Britain of 1876 14,567 Australia Sept. 12, 1934 of 1933 

